The present invention relates generally to coatings and more particularly to coatings which prevent corrosion and are thermally stable at high temperatures.
Many metal surfaces require the protection of a coating which will resist temepratures of 500.degree. F. to 700.degree. F. and also protect the metal surface against corrosion. An example of a surface requiring this kind of protection is the low carbon steel surface of the heat shields around aircraft turbine engines. In addition to being heat- and corrosion-resistant, the protective coating for such a surface should have good adhesion with minimal surface preparation and be easily appliable. Other desirable features of a coating of this type include the ability to air-dry within about eight hours to a coating with good film integrity, and the ability to partially cure at room temperature so as not to require immediate high temperature curing.
Currently used coatings for high-temperature applications lack one or more of these qualities. Ceramic coatings and those containing silicones with methyl and phenyl groups, require a high-temperature cure before use. Others, such as catalyzed silicones, require mechanical preparation of the substrate to achieve good adhesion. No single coating currently combines all of the above desirable characteristics.